Endangered Species - Part 9 (from X-Men #202): A Medical Review
Endangered Species, Part 9
Christos Gage, writer
Scot Eaton, penciler
For the sake of argument — and comic book science — I’m willing to accept the face that there is a single “mutant gene” — the x-factor — that is present in all mutants. It has vastly different effects in different people, but it is a single gene.
However, in this exchange with the Dark Beast, Henry McCoy suggests that there is not just a mutant gene, but a mutant chromosome. This is a completely different kettle of fish. A chromosome consists not of a single gene, but hundreds — if not thousands — of genes, along with regulatory DNA, junk DNA, and various proteins.
A human has 46 chromosomes (23 pairs of chromosomes, 1 chromosome from each pair is inherited from each parent). If McCoy’s statement is correct, then mutants have 47 chromosomes — an odd number. That really screws up reproduction, inheritance, and meiosis, which rely on equal pairs of chromosomes to work right. It also makes be wonder why it took Marvel Universe scientists decades to find a blood test to detect mutants — an extra chromosome is hard to miss.
All this speculation is probably moot because most likely McCoy (or Gage) just misspoke and meant to say “gene” instead of chromosome. (…or else the mutant genome is more screwed up than I ever possibly imagined.)
I was also planning to rebut Hank’s bad HIV analogy (mainly that HIV is undetectable because there only a few copies hidden among the millions of cells of the human body, as opposed to the fact that each one of these millions of cells* has a copy of every gene), but the Dark Beast calls him on it in the next panel. When the Dark Beast smacks down your analogy, you know it’s a bad one.
Finally, let me just point out the irony of Henry McCoy, whose teammates include a man who shoots optic force beams from his eyes — Newton be damned — and another who has wings a fraction of the wingspan required to fly, dismiss something as “not scientifically possible.”
*Not counting red blood cells, which lose their nucleus (and thus chromosomes) early in their lifespan.
October 8th, 2007 at 3:27 am
I would recall that in X-Men 2 they suggested that the X-gene is inherited from the mother. Since then I have tried to figure how that would work out..
October 8th, 2007 at 5:22 am
http://content.karger.com/ProdukteDB/produkte.asp?Doi=71608
says
“The chromosome numbers of Tokudaia osimensis from Amamioshima and of Tokudaia sp. from Tokunoshima are 2n = 25 and 2n = 45, respectively, with a putative single X chromosome.”
October 8th, 2007 at 6:04 am
Could it be that mutants have a particular chromosome in place of a normal one?
October 8th, 2007 at 6:56 am
I’d think “Mutancy” is more like a polygene thing, like type 2 diabetes.
October 8th, 2007 at 7:20 am
I just can’t get over how Hank looks more like the Cowardly Lion…
October 8th, 2007 at 8:02 am
Isn’t DOWNS SYNDROME the situation where there is an extra chromosome?
If I recall, there are TWO # 21 chromosomes, giving a total of 47 instead of the usual 46.
~P~
P-TOR
October 8th, 2007 at 10:19 am
Actually, that’s THREE #21 chromosomes (chromosomes normally come by pairs). Hence “trisomy 21″.
October 8th, 2007 at 10:20 am
Re: the wings thing, I always assumed winged characters (outside Thannagarians, who have their own explanation) were latent telekinetics with a mental block that prevents them from using it externally, along with having wings. That explains why they can carry one, two, even sometimes three other people while flying as well.
October 8th, 2007 at 1:00 pm
There’s some conjecture that the Y chromosome is dissapearing (and has in some species of vole).
October 8th, 2007 at 1:35 pm
If mutant DNA was only inherited from the mother, the most likely explanation would be mitochondrial DNA. There are some diseases linked to this, including MELAS and a few other myopathies and an optic neuropathy. An alternative explanation would be genomic imprinting (responsible for the diseases Beckwith-Wiedemann, Prader-Willi, and Angelman Syndromes).
October 8th, 2007 at 6:28 pm
“There’s some conjecture that the Y chromosome is dissapearing (and has in some species of vole).”
http://biolog-e.ls.biu.ac.il/faculty/wides/80-855/SRYevol.pdf
“SRY can indeed disappear. It has done so in two species of the mole vole Ellobius [46]. In E. lutescens, both sexes are XO, and in E. tancrei, both sexes are XX, with one X inactive. A third species, E. fuscocapillus, has perfectly normal XY males and XX females. For many years it was thought that the sex-determining and differentiating genes on the Y had merely been translocated to another chromosome in the complement. However, it is now clear that although the E. fuscocapillus Y bears quite a normal SRY and ZFY, there is no SRY or ZFY in E. lutescens or E. tancrei. Evidently a new sex-determining system took over in a common Ellobius ancestor.”
“And how could the entire Y chromosome have been
lost in mole voles without imposing infertility on
Y-less males? This surely must have happened in
stages (Fig. 5), in which sex and spermatogenesis
genes were lost and each function replaced by a gene
on the X or an autosome. The loss of each gene would
further destabilize the Y chromosome, making loss
even more likely.”
“So how long have we got? A simplistic calculation
of the rate at which genes were deleted from the Y can
be made from the number of genes that disappeared
from the conserved and the added regions over the
past few hundred million years. The ancient part of
the Y was once homologous to the X conserved region,
which contains about 1000 genes. Only four survive.
Thus more than 995 genes have been lost since the Y
began to differentiate 170–310 Myr ago, giving an
attrition rate of 3–6 genes per Myr. Likewise, only
about 20 genes remain on the Y added region, out
of an original 500. Thus 480-odd disappeared over
the last 80–130 Myr, giving an estimate, again,
of 4–6 genes per Myr. At this rate, the human
Y chromosome might last another 10 Myr.
“Rashly assuming that our species lasts that long, what will become of us when the Y chromosome runs out of puff? Will human sex and fertility decline to zero, leading to our extinction? A more likely scenario is that first fertility genes will go, one by one, as their function is replaced by autosomal genes, then SRY will be replaced by another gene in the sex determining pathway. Accumulation of new variants at the site of this new sex-determining gene will start the whole process of sex chromosome differentiation all over again. Maybe this will happen more than once, independently. Populations with different sex-determining genes will not have much luck interbreeding, so this may well prove a speciating event that separates two new hominid species from us, their parent population.”
October 8th, 2007 at 11:43 pm
My rationalization is that the x-factor makes you a marvel mutant and possibly various forms or degrees of it determines your maximum power level, but other details of your overall genetic makeup determine the precise mutant abilities manifested.
Also yeah ‘impossible’ takes on whole new meanings when you’re personal friends with people like Jean Grey and the walking ice cube. Or a man who could make right angle turns while _running_ over a hundred miles per hour.
As long as I’m here. Remember the guilt trip Hank got for being interested in the mutant ‘cure’ a while back?
Let’s review Doctor McCoy’s genetic history: Born a mutant, further mutated to furry form by chemical exposure, then reverted years later by second chemical exposure as part of the set up for X-Factor as the original X-Men in their original form, modified by Apocalypse, then returned to his furry form by intercepting the mutagenic kiss Infectia had intended for Iceman, eventually followed by secondary mutation to ridiculous feline look.
I think the ‘letting nature take it’s course’ ship has sailed, if he doesn’t want to look like Bill the Cat he doesn’t have to.
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